This invention relates to an outline forming method and apparatus for printing or displaying characters and the like utilizing outline fonts. Further, the invention relates to a method and apparatus for storing outline data, which is used in outline formation for the display and printing of characters or the like, in an outline forming apparatus of the above-mentioned kind.
In general, an outline font is composed of outline data of a character represented by straight lines and curves. A cubic Bezier curve, spline curve or circular arc generally is used as the curve.
Such outline data represents the data of a font having a specific thickness (hereinafter referred to as “weight”). A light font (a font whose weight is light) is represented by outline data for a slender font, and a bold font (a font whose weight is heavy) is represented by outline data for a bold font. In this specification, “weight” is a numeral value representing the thickness of the character, “thickness” is a term for representing the thickness of the contour and “outline” has the meaning of contour.
Accordingly, in order to display or print characters or the like which rely upon fonts having a plurality of weight in the example mentioned above, a problem encountered is that outline fonts having a plurality of weights must be provided for each and every weight.
A system proposed to solve this problem makes it possible to form an intermediate outline font from a bold outline font and a light outline font. However, outline fonts having any desired weight cannot be produced.
Thus, since ordinary outline data does not contain information relating to movement of each control-point for dealing with any weight, the position of each control-point cannot be acquired for any weight.